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nnAsMUsD. LnAvrrr, Jn., or CAMBRIDGE, Massaoirosnrrs.`

IMPROVEMENT IN STEAM-BOWERS.

Specification forming part of Letters Patent No. l, dated June 29, 1875;application filed January 13, 1375.

To all whom it may concern Be it known that I, ERASMUS D. LEAVITT, Jr.,of Cambridge, in the county ot Middlesex and State of Massachusetts,have invented certain Improvements in Steam-Boilers, of which thefollowing is a specification My improvements relate to that variety ofcylinder-boilers which are set in two tiers, one above the other, andare connected together by upright passages, and are inclosed in a brickor other furnace, the lower boilers being filled with water, and theupper ones partly tilled with water and partly with steam g and thepurpose of the invention is to so arrange the passages as to insure amore perfect circulation of the water in the boilers, and prevent thelodgment of the steam or of the sediment in places that might endangerthe boilers by overheating them.

The first part of my invention consists in the arrangement ot'a seriesof waterlegs, connecting the upper boiler or boilers with the lowerboiler or boilers in two or more rows on each boiler, so that a part ofthem are connected with the upper boiler or boilers at the lowest point,and extend downward, and are attached toward the side of the lowerboiler below the top; and the other water-legs are attached to the lowerboiler or boilers at the highest point, and extend upward and areattached toward the side of the upper boiler or -boilers above thelowest point, as will be described. By this means a free circulation ofthe water will be established, and the steam formed in a lower boilerwill be prevented from lodging at the top, but rise with the current ofwater directly into the upper boiler, and the sediment of the upperboiler will not be deposited upon the bottom of it over the lire, butwill be carried down with the descending current of water and depositedon the bottom of the lower boiler below the lire, and thus avoid alldanger of blistering the iron by reason of the deposit.

The second part ot1 my invention consists in the arrangement of thewater-legs so that each of the lower boilers will be connected with twoor more of the upper ones, by which the circulation of the water andpressure of steam will be more equally distributed, as will be morefully described and shown.

Vand to the lower boilers at one side In the drawings, Figure 1 is atransverse sectional elevation of a set of fire-boilers, with theinterior of the brick-work of the furnace shown by the dotted lines.Fig. 2 is a side elevation of the front portion of the same, the dottedlines also showing the interior of the brick-work of the furnace.

Five boilers are represented in the drawings as forming the set, withthree of them termin g the upper tier, and two of them the lower tier.

A A A are the upper boilers, and B B the lower ones. They are simplyplain cylinderboilers, ot' the desired length, and are con- .nected witheachother throughout theirlength by several lines of water-legs, as willbe described. C C', &c., are the cylindrical waterlegs or passages whichconnect the lower boilers with the upper ones. The legs C are connectedwith the lower boilers at the top directly over the center, and to thelower side of one ofthe upper boilers at one side of the center, andextend some distance up its side and the legs C are attached to thebottom of the upper boilers directly below the center, of the center,according to its position, as shown in Fig. 1 of the drawings.

By this arrangement of the legs the currents of water will flow upwardthrough the legs C and downward through the legs C', and by means of theduplica-te connections ot' each lower boiler'with two upper ones a freeand active circulation will be maintained throughout them all.

The front ends of the lower boilers are made considerably shorter thanthe upper ones, and leave a suiiicient space for the lireplace,bridgewall, and ilue, as is seen in Fig. 2; and the lower boilers are soclosed in by the brick-work as to leave their upperparts exposed to thedirect action ot' the lire.

The boilers are made long, like the ordinary cylinder-boilers, and theyare connected by the water-legs throughout their length to insure a freecirculation in all parts. f

What I claim is- 1. The combination and arrangement of a set of two ormore boilers in two tiers, each lower boiler being connected with anupper one by two rows of water-legs, one of them attached to the top ofthe lower boiler and being connected With a separate boiler of thetoward the side of the upper one, and the upper tier, substantially asdescribed. other row attached to the bottom of the upper Executed 7thJanuary, 1875.

boiler and toward the side of thelower one,

substantially as described. E. D. LEAVITT, JR.

2. The combination with the lower boiler of Witnesses:

two duplicate rows of Water-legs, each dupli- JAMES W. POTTER,

cate series operating as described, and each WM. C. HiBBARD.

